Signatures of QGP in PHOBOS
Medium effects:
The ? meson is an ideal probe for the properties of the hadronic medium in which it forms. The important variable is the pt dependence of the ? width (larger pt corresponds to a shorter time in the hadronic medium).
Global variables:
Events with an unusually large number of particles or unusually large fluctuations in dN/d? d? are likely to be characteristic of a phase transition.